I beg to differ with Gov. Chris Christie that we need all the facts before any conclusions can be drawn about the killing of Michael Brown, in Ferguson, Mo. (“Christie on Mo. shooting: Too soon to draw conclusions,” Aug. 20).

What we do know is that Mr. Brown was unarmed and shot in broad daylight. Surely there should be a presumption under those circumstances that excessive force was used. That presumption could, of course, be rebutted by showing that the victim was, for example, a martial arts expert who could inflict lethal blows with his hands or feet.
But an unarmed, significantly overweight 18-year-old cannot seriously be construed to pose a threat of serious bodily harm to a trained police officer, even if he was prepared to engage in fisticuffs, and it would certainly not require six bullets to eliminate whatever threat he posed.

It is clear to me that the police effectively have a license to kill on the flimsiest of pretexts in this country. This impression was reinforced by the justifications offered by police officials of the subsequent killing in St. Louis, last Tuesday, of a mentally ill individual who was brandishing a knife. The video released of this killing shows the individual ambling toward two officers, who then both shot him multiple times until he fell lifeless to the ground, when a few judicious shots to the legs, say, would surely have served the purpose of incapacitating him.

Police policies and police culture, not merely racism, are causing young black American males to be killed by the police with nauseating regularity in this country.